How to Pour a Small Concrete Slab for a Shed

Mark the site where you want to put the shed. Use a can of spray paint to lay out quickly the location of the pad. Check to make sure it is not in a low area that will flood when it rains. Other things to check for are easements, setbacks or any other neighborhood restrictions on the shed's placement. You can find this information in the closing documents you received when you purchased your home.

Hammer two 1 by 2-inch stakes into the ground along one edge of the shed. Place them 2 feet past each corner of the shed walls. Run a piece of yellow builder's twine between the two stakes about 3 inches above the ground. Tie it into place and cut off the excess string. Mark the string on one side to indicate that corner's point. Hammer in a stake 2 feet past the point outside the shed's pad area. Tap a stake into the ground on the opposite corner, placing it 2 feet past where the corner will be. Square the corner of the shed using the 3, 4, 5 rule. Measure 3 feet from the corner of the first string and place a mark at that point. Measure 4 feet from where the two strings intersect and place a mark at 4 feet from the corner. Have a partner move the twine left or right until the distance between the 3-foot and 4-foot marks equals 5 feet. Nail the 1 by 2 stake into the ground at that location to fix the corner in place. Repeat this step for the other 3 corners of the shed's pad. This will set up construction lines that are square for your shed.

Dig the sod out within the pad. Keep the pad level within the twine area. Dig a footing around the perimeter 8 inches wide and 4 inches deep. A spade shovel will work best for this step.

Cut two 2 by 4's that are a foot longer than the longest side of your shed. Place one against the twine for that wall. Hammer in 1 by 2 stakes so that you can nail the 2 by 4 against them. The stakes need to be placed on the outside edge of the 2 by 4 frame. You want the inside edge of the 2 by 4 to line up perfectly with the builder's twine. Place a 4-foot carpenters level across the 2 by 4 frame. Tap the stakes in so that the 2 by 4 is level. Use a hand saw and cut the stakes level with the top of the 2 by 4.

Cut two more 2 by 4's the length of the other two walls. Repeat step 4 for the remaining sides of the pad. When you are finished the 2 by 4's will make up a framework to pour the concrete foundation for the shed. A circular saw will work for this step.

Using a pair of wire cutters, cut and place some wire fencing to set inside of the foundation. This will strengthen the concrete pad. Wire fencing will work great for this.

Pour concrete into the form work while pulling the wire fencing up a little so that the concrete will be around the wire fencing and not just sitting on top of it. Use a 2 by 4 that is longer than your foundation to level the concrete. With the help of a friend saw the 2 by 4 back and forth across the length of the concrete pad, this levels the concrete and pushes the excess concrete ahead of the 2 by 4.

Edge the concrete with a concrete edging tool and let the concrete dry overnight.

Remove the form work and your concrete pad is ready build upon.